Process of making screens for projection.



any convenient manner, as for example,

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the uncoated side of the oilcloth THOMAS A. EDISON, 0F LLEWELLYN PARK at arr raanaar WEST ORANGE, NEW JERSEY, ASSIGNOR TO THOMAS A. EDISON, INCORPORATED, OF WEST ORANGE, NEW JERSEY, A CORPORA- rnocnss or MAKING scnnnns m rnoano'rroit.

actate;

No Drawing.

To all whom it may concern:

Be it known that I, THOMAS A. Enrson, a citizen of the United States, and a resident of Llewellyn Park, West Orange, Essex county, New Jersey, have invented certain new and useful Improvements in Processes of Making Screens for Projection, of which the following is a description...

My inventlon relates to screens having a partlally reflecting surface and particularly adapted for use in the projection of motion and other pictures, and to a simple, eflicient and cheap process for making said screens.

In my improved process I make use of ordinary oilcloth or its equivalent, and preferably I employ smooth oilcloth of white or other light color. Ordinary oilcloth consists of a backing or base of flexible fabric having adhering thereto a thin coating which contains pigments or filling materials or a mixture of the same, and oxidized or dried linseed oil or other drying oil, such as ong or chinese wood oil, or a mixture of the same. In carrying out my improved process, the oilcloth is heated in y heating the portion to be treated upon a hot plate or by passing it over a heated roller, being in contact with the heated plate or roller. The plate or roller may be heated in any suitable manner, as for example, electrically or by using steam. I have found that a suitable temperature is afforded by steam at about 100 pounds pressure. The oilcloth coating becomes softened and somewhat stickywhen heated, and I then apply to the surface of the softened and sticky coating powdered material suitable for producing the desired partially reflecting surface for the screen.

'The powdered material preferably contains Specification of Letters Eatent.

Application filed June 24, 1912.

Jlatented May 2i, rare. Serial N0. 705,648.

heres tenaciously to the oilcloth coating in a thin smooth layer or coating having a reflecting surface. A brush having moderately stifi', fine bristles close together is preferably employed. In order to make the powder adhere to the oilcloth surface, some, but not a great amount of rubbing is necessary. Any excess of powdered material not adhering to the oilcloth may be brushed off with a soft brush or otherwise removed. The oilcloth thus treated is then permitted to cool and a drying mixture is sprayed over its surface from an autoinizer, such as an air brush, or in any other suitable manner. A

suitable drying mixture for this purpose consists of linseed oil, preferably boiled, turpentine, and white Japan drier in the following proportions 10 parts of linseed oil.

5 parts of turpentine.

5 parts of white apan drier.

After the surface has been sprayed, the product is permitted to dry and is then ready for use. The oilcloth may be cut into sizes suitable for screens before treatment, or rolls or large pieces of oilcloth may be treated and the product out into suitable sizes for screens at the end of the process.

The application of the final coating of drying nnxture serves to keep the powdered material from rubbing ofl or from being fingeranarked, prevents the metallic coating or bronze from tarnishing, and produces a screen having a somewhat dull surface which is more desirable for projection purposes than a screen having an excessively bright surface.

I may also corrugate slightly the finished surface of the screen in order to increase the angle within which an imageprojected on the screen may be viewed as a clear and distinct picture. The corrugation may be performed by producing slight grooves or depressions in the finished surface by any suitable means, as for example, a'marking tool, such as a roller havin stantially V-shaped ri s, the edges of which produce the depressions in the screen surface. The depressions are preferably formed in straight parallel lines close together, and

circumferential sub-' horizontal angle within which clear and distinct projected pictures may be observed.

My improved screen is flexible and may therefore be rolled and unrolled, and the metallic coatin is very adherent and is not damaged by rolling or unrolling or by rough handling. The clearness and dlstmctness of projected pictures is much enhanced by the use of my improved screen, due to the greater amount of light reflected from a screen of this character than from a screen having a more light absorbent surface. My improved process is simple, cheap and easily carried out, and a surface of the character desired is obtained with a very small amount of powdered material per unit of area.

I aving now described my invention, what I claim as new therein and desire to protect by Letters Patent is as follows:-

I. The process of making screens for projection purposes, which consists in heating oilcloth until the oilcloth surface becomes soft and somewhat sticky, applying powdered material containing a metal'to the softened and sticky surface, and rubbing the said material into the surface, substantially as described.

2. The process of making screens for pro jection purposes, which consists in heating oilcloth until the oilcloth coating becomes soft and somewhat sticky, applying powdered material containing a metal thereto, rubbing the powdered material into the surface, permitting the product to cool, applying a thin coatin of drying oil to the metallic surface, an permitting the final coating to dry, substantially as described.

3. The process of making screens for pro jection purposes, which consists in heating oilcloth until the oilcloth coating becomes soft and somewhat sticky, applyingpowdered material containing a metal thereto, rubbing the powdered material into the surface, permitting the product to cool, applying a thin coating of drying oil to the metallic surface, permitting the final coating to dry, and corrugating thesurface, substantially as described.

4. The process of making screens for projection purposes, which consists in applying heat to a fabric having adhering thereto a coating capable of being rendered soft and somewhat sticky by heating, applying powdered material containing a metal to the softened and sticky surface of the heated coating, and rubbing the said material into the surface, substantially as described.

5. The process of making screens for projection purposes, which consists in heating a fabric having adhering thereto a'coating capable of being rendered soft and somewhat sticky by heating, applying powdered material containing a metal to the surface of the heated coating, rubbing the powdered material into the surface, permitting the product to cool, applying a thin coatingof drying oil to the metallic surface, and permitting the final coating to dry, substantially as described.

6. The process of making screens for projection purposes, which consists in heating a fabric having adhering thereto a coating capable of being rendered soft and somewhat sticky by heating, applying powdered material containing a metal to the surface of the heated coating, rubbing the powdered material into the surface, permitting the product to cool, applying a thin coating of drying oil to the metallic surface, permitting the final coating to dry, and corrugating the surface, substantially as described.

7. The process of making screens for projection purposes, which consist in applying heat to a fabric having adhering thereto a coating capable of being rendered soft and somewhat sticky when heated, applying powdered material containing a metal to the soft and sticky surface of the heated coating, rubbing the powdered material into the surface, permitting the product to cool, applying a thin coating of drying oil containing linseed oil to the metallic surface, and permitting the final coating'to dry, substantially as described.

8. The process of making screens for projection urposes, which consists in treating oilc 0th to render the oilcloth coating soft and somewhat sticky, applying powdered material containing a metal thereto, applying a thin coating of drying oil to the metallic surface, and permitting the final coating to dry, substantially as described.

9. The process of making screens for projection purposes, which consists in heating a fabric having adhering thereto a coating capable of being rendered soft and somewhat sticky by heat, applying powdered material containing a metal to the surface of the heated coating, applying a thin coating of drying oil to the metallic surface, and permitting the final coating to dry, substantially as described.

This specification signed and witnessed this 19th dayof June, 1912 THOS. A. EDISON.

Witnesses .llENRY LANAHAN, ANNA R. KLEIIM. 

